This invention pertains to the art of bearing constructions and more particularly to retainers or cages employed to maintain appropriate spacing between individual bearing members.
The invention is particularly applicable to a snap-in ball retainer or cage for a ball bearing assembly wherein the retainer comprises a one-piece molded plastic or nylon construction which snaps onto or captures the ball members intermediate inner and outer bearing races and which also includes retainer pilot means as a part thereof. While the invention will be described with particular reference to this type of construction, it will be appreciated by those skilled in the art that the invention has broader applications and may be used in other environments.
Generally, bearing cages for ball type bearing assemblies are provided to maintain proper spacing between the ball members interposed between inner and outer bearing races. In high speed bearing applications, the retainer or cage loses its stability which has an overall detrimental effect on bearing efficiency.
So-called snap-in type bearing retainers are themselves known in the art as shown, for example, in the commonly assigned U.S. Pat. No. 4,040,687 to Rogers. There, a one-piece retainer molded of reinforced plastic material is provided which includes spaced apart ball receiving pockets at spaced intervals circumferentially of a retainer body and opening axially outward thereof. At least some of the ball receiving pockets are configured so as to capture an associated ball member therein. This type of retainer or cage advantageously allows retainer installation into the bearing assembly axially from one side thereof to thereby facilitate ease of assembly for the overall bearing. However, the construction and arrangement disclosed by U.S. Pat. No. 4,040,687 does not provide any means to pilot the retainer relative to the bearing races so as to eliminate retainer instability during high speed operations.
U.S. Pat. Nos. 3,649,093 to Muratore, et al. and 3,506,316 to McKee disclose prior ball retainers or cages which include pilot means associated therewith. However, and while generally addressing the aforementioned control and instability problems, U.S. Pat. No. 3,649,093 discloses a two-piece separator which must be assembled from opposite sides of the associated bearing assembly as by rivoting or the like in order to capture and position the individual ball members relative to each other. U.S. Pat. No. 3,506,316 provides axially open ball member receiving slots in a side mounted bearing cage with cage piloting being effected directly in the circumferential raceway of one of the inner and outer races.
It has, therefore, been considered desirable to develop a bearing retainer or cage to overcome the foregoing problems as well as others and provide a one-piece snap-in type retainer construction which would facilitate ease of installation and capture of ball members in individual retainer pockets. At the same time, the retainer would include means for piloting it off of the inner and outer bearing races to provide stability during high speed bearing applications. The subject invention meets these needs and provides such a retainer in a manner which will be described hereinafter.